21383031 has 8 divisors (see below), whose sum is σ = 29750400. Its totient is φ = 13635512.

The previous prime is 21383029. The next prime is 21383053. The reversal of 21383031 is 13038312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21383031 - 2¹ = 21383029 is a prime.

It is a super-2 number, since 2×21383031² = 914468029493922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21382989 and 21383007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21383071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154881 + ... + 155018.

It is an arithmetic number, because the mean of its divisors is an integer number (3718800).

Almost surely, 2^21383031 is an apocalyptic number.

21383031 is a deficient number, since it is larger than the sum of its proper divisors (8367369).

21383031 is a wasteful number, since it uses less digits than its factorization.

21383031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309925.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21383031 is about 4624.1789541496. The cubic root of 21383031 is about 277.5597079540.

The spelling of 21383031 in words is "twenty-one million, three hundred eighty-three thousand, thirty-one".